import math
def min_desk(p1, p2, p3):
    if p1%2 != 0:
        p1+=1
    if p2%2 != 0:
        p2+=1
    if p3%2 != 0:
        p3+=1
    return int((p1+p2+p3)/2)

assert min_desk(20, 21, 22) == 32
assert min_desk(30, 29, 31) == 46
assert min_desk(17, 15, 19) == 27
'решение зачтено'